<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>三角形</title>
    <style>
        /*直角三角形*/
        .triangle1{
            width: 0;
            height: 0;
            border:50px solid;
            /*通过改变边框颜色可以改变三角形的方向，原理是边框等分的原理*/
            border-color: skyblue transparent transparent skyblue;
        }

        .triangle2{
            margin-top: 10px;
            width: 0;
            height: 0;
            border:50px solid;
            border-color: tomato transparent transparent  transparent;
        }
        
    </style>
</head>
<body>
    <div class="triangle1"></div>
    <div class="triangle2"></div>
   
</body>
</html>